Papers by Carlos Suarez-Quian
Journal of andrology
Page 1. 601 Journal of Andrology, Vol. 21, No. 5, September/October 2000 Copyright American Socie... more Page 1. 601 Journal of Andrology, Vol. 21, No. 5, September/October 2000 Copyright American Society of Andrology Minireview Laser Capture Microdissection: A New Tool for the Study of Spermatogenesis CARLOS A. SUA ...
Journal of reproduction and fertility, 1994
The modulation of transferrin secretion by FSH and epidermal growth factor (EGF) was studied in h... more The modulation of transferrin secretion by FSH and epidermal growth factor (EGF) was studied in highly pure, primary cultures of immature rat Sertoli cells grown on a reconstituted basement membrane (Matrigel) in bicameral chambers. Sertoli cell purity was assessed by (1) morphometry, (2) alkaline phosphatase cytochemistry (a specific marker enzyme for peritubular cells) and (3) immunocytochemistry for the alpha-isoform of smooth muscle actin in contaminating peritubular cells. Results revealed a less than 0.5% peritubular cell contamination. During initial periods of culture with EGF or FSH alone or in combination, both EGF and FSH alone maintained transferrin secretion over basal values and their effects were additive. At subsequent times, EGF alone maintained transferrin secretion, but to less extent than did FSH alone, and inhibited significantly the ability of FSH to maintain transferrin secretion. The ratio of polarized transferrin secretion in response to FSH, EGF, or in comb...
Journal of the National Cancer Institute, 1984
BRO human melanoma cells were prelabeled in vitro with [125I]5-iodo-2'-deoxyuridine ([125I]Id... more BRO human melanoma cells were prelabeled in vitro with [125I]5-iodo-2'-deoxyuridine ([125I]IdUrd) and inoculated into NIH-II nude mice ip, im, sc, or iv. Saline or diphtheria toxin (DT), which is selectively toxic to human cells compared to those of mice, was injected, and the loss of 125I from the animals was monitored daily with a whole-body gamma scintillation detector. For most of the inoculation sites DT accelerated the rate of 125I excretion and in all cases was cytotoxic for the inoculated cells as determined by host survival or measurement of visible tumor growth. Differences between the rates of 125I loss for DT-treated mice compared to untreated mice were most evident for cells inoculated ip or im. These results indicate that [125I]IdUrd prelabeling of human tumor cells inoculated in nude mice offers a rapid method for determination of cytotoxicity in vivo.
Review of Scientific Instruments, 1999
We have developed a new form of laser capture microdissection (LCM) optimized for isolating and c... more We have developed a new form of laser capture microdissection (LCM) optimized for isolating and concentrating single cells from a tissue slide for subsequent molecular analysis. In LCM an infrared laser diode is used together with a microscope to locally melt a thin film of ethylene vinyl acetate (EVA) placed in contact or close proximity to microscopically targeted cells. Since
The Journal of Cell Biology
Sertoli cell preparations isolated from lO-day-old rats were cultured on three different substrat... more Sertoli cell preparations isolated from lO-day-old rats were cultured on three different substrates: plastic, a matrix deposited by co-culture of Sertoli and peritubular myoid cells, and a reconstituted basement membrane gel from the EHS tumor. When grown on plastic, Sertoli cells formed a squamous monolayer that did not retain contaminating germ cells. Grown on the matrix deposited by Sertoli-myoid cell co-cultures, Sertoli cells were more cuboidal and supported some germ cells but did not allow them to differentiate. After 3 wk however, the Sertoli cells flattened to resemble those grown on plastic. In contrast, the Sertoli cells grown on top of the reconstituted basement membrane formed polarized monolayers virtually identical to Sertoli cells in vivo. They were columnar with an elaborate cytoskeleton. In addition, they had characteristic basally located tight junctions and maintained germ cells for at least 5 wk in the basal aspect of the monolayer. However, germ cells did not differentiate. Total protein, androgen binding protein, transferrin, and type I collagen secretion were markedly greater when Sertoli cells were grown on the extracellular matrices than when they were grown on plastic.
Annals of the New York Academy of Sciences
... CARLOS A. SUAREZ-QUIAN,b MARK A. HADLEY, and MARTIN DYM Georgetown University School of Medic... more ... CARLOS A. SUAREZ-QUIAN,b MARK A. HADLEY, and MARTIN DYM Georgetown University School of Medicine-School of Dentistry Washington ... Culture of Sertoli cells and preparation for electron microscopy was carried out as described previo ~ sly ~ ~ but with the following ...
The Anatomical record, 1992
We examined the disassembly and reformation of the Golgi apparatus as a function of the cycle of ... more We examined the disassembly and reformation of the Golgi apparatus as a function of the cycle of the seminiferous epithelium in adult rats during stages XIII and XIV, i.e., just prior to and during meiosis I and II. Serial section analysis of primary spermatocytes at metaphase I demonstrated the presence of two Golgi complexes. At the ultrastructural level, these Golgi complexes were shown to be composed of stacks of cisternae and vesicles, with each stack having a varying number of saccules. Although Golgi complex intermediates resulting from the process of organelle disassembly were not clearly identified in diplotene spermatocytes immediately prior to nuclear envelope vesiculation, we did observe clusters of vesicles resembling the "nuage," with each cluster varying in size and number of vesicles. Meiosis I results in the formation of secondary spermatocytes that exhibit a well-formed spherical Golgi complex approximately half the size of the diplotene spermatocyte Golg...
Journal of andrology
The human vas deferens (VD) is often considered simply as a conduit to transfer mature sperm from... more The human vas deferens (VD) is often considered simply as a conduit to transfer mature sperm from the epididymis to the ejaculatory duct. The cells that make up the epithelium of the VD, however, exhibit many characteristics of cells found in more complex epithelia, which are involved in absorption and/or secretion. In the present investigation, morphometry was utilized to characterize in detail the changes incurred by the human VD during its development, growth, and aging and to determine if these changes correlate with testicular maturation. In addition, the specific types of keratins present in the epithelial cells were defined, as well as desmin distribution in the muscular layers, during the various phases of the development, growth, and involution of the human VD. Results of the morphometric study are consistent with the interpretation that the development, growth, and aging of the VD are delayed, but parallel to, the identical phases exhibited by the human testis. Further, a ...
Journal of steroid biochemistry, 1986
The hypothalamic decapeptide, GnRH, stimulates LH and FSH release from pituitary gonadotrophs. Ma... more The hypothalamic decapeptide, GnRH, stimulates LH and FSH release from pituitary gonadotrophs. Many synthetic peptide analogs, both agonist (GnRH-A) and antagonist (GnRH-AT), have been developed which bind specifically to the GnRH receptor. We have utilized highly potent GnRH-A and GnRH-AT analogs labeled with 18 nm colloidal gold to analyze ultrastructurally the events of binding and interiorization of these specific ligands by gonadotrophs in vitro. To examine internalization of GnRH-A-gold, gonadotrophs were cooled to 4 degrees C and equilibrated with the ligand for 1 h. Next, the cells were either fixed immediately or warmed to 37 degrees C for various times (5, 15 and 30 min) and prepared for electron microscopy. For GnRH-AT-gold, which binds slowly at 4 degrees C, the ligand was incubated with gonadotrophs at 37 degrees C for 15, 30 and 60 min, and the cells were processed for electron microscopy at each time point. In both cases, control gonadotrophs were also incubated in an...
Journal of andrology
Degeneration of primary spermatocytes by apoptosis occurs during normal spermatogenesis, as well ... more Degeneration of primary spermatocytes by apoptosis occurs during normal spermatogenesis, as well as in several pathological conditions, including exposure to specific testicular toxicants. The mechanisms that regulate the death and survival of primary spermatocytes, however, are still not well understood. The recent localization of estrogen receptor beta (ERbeta) and P450 aromatase in pachytene spermatocytes suggests a role for estrogens in this step of spermatogenesis. Using a well-known model of pachytene spermatocyte apoptosis in adult rats consisting of the administration of methoxyacetic acid (MAA), we investigated the participation of ERbeta during the initial phase of apoptosis, prior to germ cell loss. Adult rats were treated with a single intraperitoneal dose of MAA, and DNA laddering analysis confirmed apoptotic cell death in the testis. In enriched germ cell fractions and testis from MAA-treated animals, ERbeta mRNA increased significantly at 3 and 6 hours, respectively. ...
The Anatomical Record, 1991
A morphological and immunocytochemical study of the Golgi apparatus in pachytene spermatocytes wa... more A morphological and immunocytochemical study of the Golgi apparatus in pachytene spermatocytes was performed in an effort to correlate the structure and function of this organelle during meiotic prophase. In stages 1-111 of the cycle, the Golgi complex of pachytene spermatocytes is a flattened discoid, 0.5-1 pm in diameter, composed of vesicles interspersed with classically described Golgi cisternae. During subsequent maturation of pachytene spermatocytes (stages IV-XIII), the size of the Golgi complex increases significantly, attaining a size of 2-3 pm. However, unlike pachytene spermatocytes of stages 1-111, the majority of the Golgi complex of more mature spermatocytes is characterized by an abundance of distinct stacks of cisternae interspersed with numerous vesicles and tubules. The composition of the Golgi complex was also studied by using two
The Anatomical Record, 1992
The epididymis, a post-testicular site required for maturation and storage of spermatozoa, is act... more The epididymis, a post-testicular site required for maturation and storage of spermatozoa, is actively involved in exocytic and endocytic events, two phenomena likely to depend on the integrity of the lysosomal system. To study the lysosomal system of the epididymis, five monoclonal antibodies, previously characterized as recognizing five distinct lysosomal integral membrane proteins (LIMPs 1-5), were used as molecular probes of lysosome distribution in cells lining the epithelium. Immunocytochemical localization of LIMPs, using biotin-streptavidin immunoperoxidase methodology, was performed on frozen sections of adult rat epididymides and in cell cultures prepared from either the caput or cauda epididymis. In frozen sections, a heterogeneous distribution of the different LIMPs along the length of the epididymis was observed. For example, the distribution of LIMP 1 (35-50 K) was detected in all cells of the caput and quite dramatically in clear cells of the distal caput, corpus, and cauda epididymis, but specifically not in the principal cells of the distal caput, corpus, and cauda. In contrast, LIMP 2 (64-71 K) was present in all cells of the epididymis, except clear cells. LIMPs 4 and 5 (93 K and 93 K) were detected in all epididymal cells, including the clear cells. Finally, whereas the regional and cell type distribution of LIMP 3 (74 K) in the epididymis was identical to that of LIMPs 4 and 5, the nature of the vesicles immunostained was distinct. In cultured cells, the general immunostaining patterns observed in vivo were maintained during the duration of the primary cultures for all five LIMPs. Our results begin to address the molecular heterogeneity of the lysosomal system along the length of the epidiymis, and may suggest in part a basis for underlying structural and functional characteristics of the epididymis leading to the sequential maturation of sperm.
Degeneration of primary spermatocytes by apoptosis occurs during normal spermatogenesis, as well ... more Degeneration of primary spermatocytes by apoptosis occurs during normal spermatogenesis, as well as in several path- ological conditions, including exposure to specific testicular toxi- cants. The mechanisms that regulate the death and survival of pri- mary spermatocytes, however, are still not well understood. The re- cent localization of estrogen receptor beta (ERb) and P450 aroma- tase in pachytene spermatocytes suggests
La funció que duen a terme els andrògens en l'espermatogènesi és, encara en certa mesura, eni... more La funció que duen a terme els andrògens en l'espermatogènesi és, encara en certa mesura, enigmàtica: mentre que llur implicació és absolutament vital en la iniciació i en el manteniment del procés espermatogènic normal, la seva funció específica encara no està definida de manera precisa. Els andrògens, com les altres hormones esteroïdals, actuen a través del seu corresponent receptor anomenat
Methods in Enzymology, 2002
Tissue and Cell, 1994
Epidermal growth factor (EGF), a potent mitogen produced primarily in the submandibular gland of ... more Epidermal growth factor (EGF), a potent mitogen produced primarily in the submandibular gland of adult male mice, has been implicated m modulating processes known to be of vital importance in the regulation of spermatogenesis.
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Papers by Carlos Suarez-Quian